Santhi Selvi, A (2009) Evaluation of the Effect of Atorvastatin on Insulin Sensitivity. Masters thesis, Stanley Medical College, Chennai.
|
Text
200100209santhi_selvi.pdf Download (412kB) | Preview |
Abstract
INTRODUCTION: The 3-Hydroxyl-3 methyl glutaryl Coenzyme A (HMG CoA) reductase inhibitors or statins have been a primary force in the management of hypercholesterolemia for many years and are important in the primary and secondary prevention of heart disease. However, increasingly it is being shown that the statins have clinical benefits that appear to be greater than those one would expect from improvement in the lipid profile alone. These pleotrophic actions include direct effects on vascular tissue, kidney, bone and glucose metabolism. The hyperinsulinaemic / insulin resistant states is a metabolic condition linked to widespread and heterogeneous clinical syndrome like hypertension, obesity, type-2 diabetes, dyslipidaemia, atherosclerosis and coronary vascular disease. About 25% of the non-diabetic population shows abnormalities of insulin sensitivity and compensatory hyperinsulinaemia. Diabetes affected 194 million people worldwide in 2003 and is estimated to affect 299 to 333 million by 2025, according to International Diabetes Federation. Various studies have observed the effect of statins on insulin sensitivity in Type 2 Diabetic mellitus. Since statins are commonly used for the treatment of hypercholesterolemia in clinical practice, it is important to know their effect on insulin sensitivity. AIMS AND OBJECTIVES: To evaluate the effects of Atorvastatin on insulin sensitivity. MATERIAL AND METHODS: The study deals with the effect of Atorvastatin on insulin sensitivity conducted at Hypertension outpatient department of Government Stanley Medical College Hospital, Chennai. Ethical approval for the study was obtained from the institutional ethical review board. Ninety patients are screened for the study from a random population of 110 hypertensive patients receiving atenolol as anti-hypertensive drug, by a random selection process, from which 68 patients are considered based on patient compliance, intelligence to understand dietary prescriptions and directions and whether free from any other disease on initial medical testing. Written consent for the study as per protocol is obtained. The patients were randomized into two groups, of 34 patients each, by a random selection process. The experimental group consisting of 34 dyslipidaemic and hypertensive patients receiving atorvastatin 10mg/day and atenolol 50 mg/day at the Hypertension OPD at Govt Stanley Medical College Hospital are chosen as volunteers and are compared with another group of 34 hypertensive patients receiving atenolol 50 mg/day only. Uniform diet pattern is prescribed to all of them. Inclusion Criteria: Dyslipidaemia, Hypertension, Age 40 to 50 years, not receiving any drugs other than mentioned above, not suffering from any other diseases. Exclusion Criteria: Those patients not satisfying the inclusion criteria are excluded. Clinical Characters of Volunteers: Clinically, both the groups show no abnormality, other than hypertension in both groups, along with dyslipidaemia in the experimental group. Data Collection: Height, Weight, BMI and blood pressure measurements were done and other information collected with the help of predesigned questionnaire. RESULTS AND OBSERVATIONS: Table – 1 shows the anthropometric and biochemical characteristics of the subject in the control and Atorvastin treated groups at the start of the study. The proportion of the male & female in both the groups was similar. Proportion of subjects having positive family history of diabetes and blood pressure in both the groups were also similar. It is found that in the group receiving atenolol and atorvastatin (experimental group), TC is reduced from initial values of 280 +/- 20 mg/dl to 202 +/- 12 mg/dl (p = 0.05). HDLC is increased from 45 +/-10 mg/dl to 52 +/- 12 mg/dl (p = 0.04). LDLC reduced from 180 +/-20 mg/dl to 148 +/-12 mg/dl (p = 0.05). VLDLC, Triglycerides values remain almost same, and changes are statistically insignificant. FBS values changed from initial 106 +/- 6 mg/dl to 88 +/-4 mg/dl (p = 0.04). In the control group receiving atenolol only, it is observed that TC is from initial values of 140 +/-20 mg/dl to 112+/-8 mg/dl. HDLC changes from 40 +/-10 mg/dl to 44 +/-9 mg/dl. LDLC changes from 110 +/-30 mg/dl to 95 +/-13 mg/dl. VLDLC, TG and FBS values remain almost same, and all the value changes are statistically insignificant. Table 4 shows serum insulin and homeostasis model assessment of insulin resistance (HOMA 2-IR) values of different groups, in order to determine insulin sensitivity. It was observed that in the experimental group, serum insulin value initially is 20 +/-5 microU/ml and finally is 18 +/-3 microU/ml (p = 0.03), and in the control group, serum insulin value initially is 18 +/-5 microU/ml and finally is 31 +/-2 microU/ml. HOMA 2 values (insulin resistance or IR) of the two groups of patients show that in the experimental group it was 4.3 +/-0.5 microU/ml initially and 4.3 +/-0.3 microU/ml finally, showing increase in insulin sensitivity by atorvastatin. CONCLUSION: 1. Statins improve insulin sensitivity even in normoglycemics and prevent the progression of IGT to type 2 diabetes. 2. Statins reduce levels of interleukin 6 and TNF through its antiinflammatory activity. These cytokines inhibit lipoprotein lipase activity and to stimulate lipolysis in adipose tissue. Atorvastatin may therefore interrupt the progression from central obesity to insulin resistance mediated by the adipose tissue derived cytokines. 3. Impaired endothelial function has been shown to correlate with insulin resistance. Atorvastatin by restoring endothelial function, may beneficially affect glucose and insulin transport. 4. Since statins are used for the treatment of hypercholesterolemia in clinical practice, it is important to know their effect on insulin sensitivity. If further studies confirm the observation that statins improve insulin sensitivity and reduce the onset of type 2 diabetes, the perceived benefit of cardiovascular intervention in clinical trials could be greatly increased and the long term cost-benefit analysis of those interventions may be more positive than previous studies have estimated.
| Item Type: | Thesis (Masters) |
|---|---|
| Uncontrolled Keywords: | Atorvastatin ; Insulin Sensitivity. |
| Subjects: | MEDICAL > General Medicine |
| Depositing User: | Subramani R |
| Date Deposited: | 23 Mar 2018 16:51 |
| Last Modified: | 24 Mar 2018 09:04 |
| URI: | http://repository-tnmgrmu.ac.in/id/eprint/6512 |
Actions (login required)
 |
View Item |
